Prior art discloses a mobile phone unit with phone book data capable of registering three telephone numbers (a telephone number for business, a private telephone number, and a telephone number of a mobile phone) for communication with one person, whereby, if a current date and time is 10 a.m. on Monday, rearranges and displays the telephone numbers in an order of “for business,” “mobile phone,” and “private,” and if a current date and time is a weekend, rearranges and displays the telephone numbers in an order of “private,” “mobile phone,” and “for business.” It has also been disclosed that changing an indication sequence of telephone numbers or mail addresses registered in an address book according to a period of time or a day of the week.
At the present, if a current date and time is 10 a.m. on Monday (business hours), displaying telephone numbers of a person to communicate in an order of “for business,” “mobile phone,” and “private,” and in this case, if the person is in an office, there is no problem. However, if the person is out of an office, for example, on a business trip, it is better to make a phone call, instead of using the telephone number “for business” whose indication sequence level is first, using the telephone number of a “mobile phone” whose indication sequence level is second. Also, if the person takes time off from work and stays home, it is better to make a phone call using the “private” telephone number whose indication sequence level is third. Similarly, it has also been disclosed that if a current date and time is a weekend (holiday), displaying telephone numbers of a person to communicate in an order of “private,” “mobile phone,” and “for business”; however, if the person is working on a holiday, it is better to make a phone call, instead of using the “private” telephone number whose indication sequence level is first, using the telephone number “for business” whose indication sequence level is third. Also, if the person is away from home, it is better to make a phone call using the telephone number of a “mobile phone” whose indication sequence level is second. As described in the foregoing, there may be a situation in which, when trying to communicate with a person, even if a user selects a telephone number whose indication sequence level is first, and makes a phone call using it, s/he cannot successfully communicate with the person, and s/he have to again browse phone book data to find a telephone number whose indication sequence level is second or lower, and again to make a phone call.